Storm-Induced Coastal Change

Dune Erosion

Dune erosion occurs when storm surge elevates waves higher on the beach, allowing them to attack and erode the coastal dune. As sand is removed from the dune, the front face becomes very steep, or scarped. The overall volume and elevation of the dune is reduced due to the erosion process (Figure 1). Dune erosion makes properties behind the dune more vulnerable to future storms and the potential for overwash (Figure 2). The eroded sediment is carried offshore and stored in large sandbars. The sand dune can recover over a period of years, gaining in elevation and volume through deposits of wind-blown sand. Because dunes rebuild over a long period, many coastal counties choose to build temporary dunes following a large storm.